Heat transfer unit, especially for a motor vehicle

ABSTRACT

The invention relates to a heat transfer unit comprising at least two heat transfer elements, especially for a motor vehicle. Said unit comprises a plurality of tubes and corrugated ribs, two side parts ( 4 ) which enclose the monoblock on the opposite sides thereof, whereby at least one side part ( 4 ) comprises at least one expansion section ( 11 ).

[0001] The invention relates to a heat transfer unit with at least twoheat transfer elements, especially for a motor vehicle, according to thepreamble of claim 1.

[0002] A heat transfer unit, especially in a monoblock version, consistsof at least two heat transfer elements in a structural unit, with theresult that construction space and production costs are saved, ascompared with a configuration with separate heat transfer elements, andof at least two side parts which frame the heat transfer unit. In suchheat transfer units, as a result of temperature changes and temporarilydifferent temperature levels associated with these in the heat transferelements, mechanical stresses occur between the individual heat transferelements on account of their different thermal expansion, and thesestresses may lead to leaks. Furthermore, in the event of temperaturechanges, the stresses associated with these between the heat transferelements and the side parts subject the ends of tubes in the heattransfer unit to load, and this may also lead to leaks here.

[0003] For this reason, DE 197 53 408 A1 proposes a heat transferelement having a rib/tube block, the side parts of which are provided,outside a net structure, with expansion joints. In this case, at leastone expansion portion is arranged level with the net structure of therib/tube block. The expansion portion may in this case be designed as afold-like expansion joint or as expansion beads with clearance portions,tensioning straps for mounting and soldering the rib/tube block beingled through the clearance portions, in order to hold the unit together.

[0004] The object of the invention is to improve a heat transfer elementof this type.

[0005] This object is achieved by means of a heat transfer element withthe features of claim 1.

[0006] According to the invention, a heat transfer unit consists of atleast two heat transfer elements and has a plurality of tubes andcorrugated ribs connected to one another in the manner of a netstructure. Furthermore, at least two side parts framing the heattransfer unit are provided, at least one side part having at least oneexpansion portion. Preferably, the at least one expansion portion runsessentially in a longitudinal direction of the side part. An expansionportion of this type allows transverse decoupling in the side part[lacuna] mechanical decoupling of two heat transfer elements. In spiteof the decoupling, a heat transfer unit according to the invention has asufficiently high stability of the side parts for transport andmanufacture.

[0007] Preferably, in addition to the expansion portion mentioned above,the at least one side part has provided in it a further expansionportion which runs in the transverse direction of the side part andallows longitudinal decoupling for the protection of the tube ends. Anarrangement of this type makes it possible for the two heat transferelements to be decoupled completely with respect to one another.

[0008] Preferably, the side part has provided in it at least oneperforation which is arranged between two expansion portions.

[0009] Preferably, the expansion portion is formed by one or morefold-like beads. If a plurality of beads are provided, these arepreferably separated from one another by perforations. In this case,preferably, the beads or perforations are in alignment with one another.This results in a better soldering of the two nets as a result of thehinge action of the side parts, since the different set behavior of thetwo nets is compensated on account of the unequal tube geometries.

[0010] Preferably, the perforations are designed to be wider than thebeads. In this case, the width of the perforations in the longitudinaldirection is preferably between five and ten times as great as the widthof the beads in the longitudinal direction of the side surface.

[0011] Preferably, the beads are designed in such a way that they areformed outwardly. This produces a relatively planar surface on theinside of the side parts.

[0012] According to a preferred embodiment, a marginal region of theside part is bent at approximately 90° along the longitudinal edge ofthe side part, and the expansion portion for longitudinal decoupling isformed by two fold-like beads. In this case, the beads are preferablydesigned in such a way that they have a mirror-symmetrical design, beingformed toward one another.

[0013] Preferably, the expansion regions are arranged in a region whichis arranged on the outside of the side parts. This produces a relativelyplanar surface on the inside of the side parts.

[0014] The invention is explained in more detail below by means of anexemplary embodiment, with reference to the drawing in which:

[0015]FIG. 1 shows a partial perspective illustration of a monoblock,

[0016]FIG. 2 shows a top view of the monoblock of FIG. 1, and

[0017]FIG. 3 shows a perspective illustration of a side part.

[0018] A heat transfer unit 1 according to the invention, in the form ofa soldered all-aluminum monoblock, has a flat-tube condenser 2, acoolant cooler 3, which comprise a plurality of flat tubes andcorrugated ribs connected to one another in the manner of a netstructure, and two side parts 4 located opposite one another.

[0019] The side parts 4 have transverse decoupling 10 in the form of anexpansion portion 11 for decoupling the flat-tube condenser 2 andcoolant cooler 3 and longitudinal decoupling 20 for the protection ofthe flat-tube ends, in the form of an expansion portion 21.

[0020] The expansion portion 11 for decoupling the flat-tube condenser 2and coolant cooler 3 is formed by a plurality of fold-like beads 12which, spaced apart from one another by perforations 13, are arranged inalignment in the longitudinal direction of the side parts 4. In thiscase, the expansion portion 11 is arranged nearer to the flat-tubecondenser 2 than to the coolant cooler 3. The width of the perforations13 in the longitudinal direction of the side parts 4 is greater than thewidth of the fold-like beads 12 in the longitudinal direction of theside parts 4, the width of the perforations 13 being approximately sixtimes as great as the width of the fold-like beads 12. According to thepresent exemplary embodiment, the fold-like beads 12 are bent outwardly,that is to say away from the flat-tube condenser 2 and from the coolantcooler 3 (see FIG. 1).

[0021] The expansion portion 21 for longitudinal decoupling 20 for theprotection of the flat-tube ends is formed by part of a marginal regionof the side parts 4 which is bent outwardly at approximately 90° andwhich is provided with a fold-like bead 22. The side parts 4 have aslot-like perforation 23 which runs in the transverse direction andextends from one marginal region to the opposite marginal region. Thefold-like beads 22 are designed in such a way that they point toward oneanother (see FIG. 2).

[0022] The beads 12 and 22 lie on the side of the side parts 4 which isarranged on the outside, so that an essentially planar surface isprovided on the inside.

[0023]FIG. 3 illustrates a perspective view as a further exemplaryembodiment of a side part 100 for a heat transfer unit, not shown, withtwo different heat transfer elements. The side part 100 likewise hastransverse decoupling between a region 110 assigned to a first heattransfer element and a region 120 assigned to a second heat transferelement. The transverse decoupling is implemented by means ofperforations 130, so that the regions 110 and 120 are connected to oneanother solely by means of webs 140, the webs 140 being configured in abent shape for improved decoupling. In order to increase the bendingrigidity of the side part 100, margins 150 in the perforations 130 areset up, so that the action of the set-up side part edges 160 and 170 isreinforced.

[0024] For longitudinal decoupling, the side part 100 has transverselyrunning perforations 180 in addition to the perforations 130. Holdingdevices 190 serve for mounting the entire heat transfer unit in a motorvehicle and, for simplification, are produced in one piece with the sidepart 100.

[0025] The side parts 4 have transverse decoupling 10 in the form of anexpansion portion 11 for decoupling the flat-tube condenser 2 andcoolant cooler 3 and longitudinal decoupling 20 for the protection ofthe flat-tube ends, in the form of an expansion portion 21.

[0026] The expansion portion 11 for decoupling the flat-tube condenser 2and coolant cooler 3 is formed by a plurality of fold-like beads 12which, spaced apart from one another by perforations 13, are arranged inalignment in the longitudinal direction of the side parts 4. In thiscase, the expansion portion 11 is arranged nearer to the flat-tubecondenser 2 than to the coolant cooler 3. The width of the perforations13 in the longitudinal direction of the side parts 4 is greater than thewidth of the fold-like beads 12 in the longitudinal direction of theside parts 4, the width of the perforations 13 being approximately sixtimes as great as the width of the fold-like beads 12. According to thepresent exemplary embodiment, the fold-like beads 12 are bent outwardly,that is to say away from the flat-tube condenser 2 and from the coolantcooler 3 (see FIG. 1).

LIST OF REFERENCE SYMBOLS

[0027]1 Heat transfer unit

[0028]2 Flat-tube condenser

[0029]3 Coolant cooler

[0030]4 Side part

[0031]10 Transverse decoupling

[0032]11 Expansion portion

[0033]12 Bead

[0034]13 Perforation

[0035]20 Longitudinal decoupling

[0036]21 Expansion portion

[0037]22 Bead

[0038]23 Perforation

[0039]100 Side part

[0040]110 First heat transfer element region

[0041]120 Second heat transfer element region

[0042]130 Perforation for transverse decoupling

[0043]140 Web

[0044]150 Set-up

[0045]160 Set-up

[0046]170 Set-up

[0047]180 Perforation for longitudinal decoupling

[0048]190 Holding device

1. A heat transfer unit with at least two heat transfer elements,especially for a motor vehicle, which has a plurality of tubes andcorrugated ribs, and with at least two side parts (4) which frame theheat transfer unit on opposite sides, at least one side part (4) havingat least one expansion portion (11), characterized in that the expansionportion (11) runs essentially in the longitudinal direction of the sidepart (4).
 2. The heat transfer unit as claimed in claim 1, characterizedin that at least one expansion portion (21) is provided, which runsessentially in the transverse direction of a side part (4).
 3. The heattransfer unit as claimed in claim 1, characterized in that at least oneperforation (13; 23) is provided in the side part (4).
 4. The heattransfer unit as claimed in claim 1, characterized in that the at leastone expansion portion (11) is formed by one or more fold-like beads(12).
 5. The heat transfer unit as claimed in claim 4, characterized inthat the beads (12) are separated from one another by perforations (13).6. The heat transfer unit as claimed in claim 5, characterized in thatthe beads (12) are in alignment with one another.
 7. The heat transferunit as claimed in claim 5, characterized in that the perforations (13)are wider than the beads (12).
 8. The heat transfer unit as claimed inclaim 4, characterized in that the beads (12) are formed outwardly. 9.The heat transfer unit as claimed in claim 4, characterized in that thebeads (12) are formed inwardly.
 10. The heat transfer unit as claimed inclaim 2, characterized in that a marginal region of the side part (4) isbent at approximately 90° along a longitudinal edge of the side part(4), and the expansion portion (21) is formed by two fold-like beads(22).
 11. The heat transfer unit as claimed in claim 10, characterizedin that the beads (22) are formed toward one another.
 12. The heattransfer unit as claimed in claim 1, characterized in that the expansionregions (11; 21) are arranged in a region which is arranged on theoutside of the side parts (4).